Stereo reconstruction generally involves using multiple images taken from different viewpoints to reconstruct a 3D model of the scene depicted in the images. Typically, this reconstruction entails recovering depth maps (often for each image) and identifying corresponding pixels between the images. These reconstructions are used for a variety of purposes. For example, depth maps obtained from stereo have been combined with texture maps extracted from input images in order to create realistic 3-D scenes and environments for virtual reality and virtual studio applications. Similarly, these maps have been employed for motion-compensated prediction in video processing applications. Still further, the recovered depth maps and correspondences have been used for view interpolation purposes to generate a “virtual” view of a scene from an arbitrary viewpoint using images associated with other viewpoints.
Unfortunately, the quality and resolution of most of today's algorithms falls quite short of that demanded by these applications. For example, traditional stereo algorithms tend to produce erroneous results around disparity discontinuities. Unfortunately, such errors produce some of the most noticeable artifacts in interpolated scenes, since disparity discontinuities typically coincide with intensity edges. For this reason, the stereo algorithm for view interpolation must correctly match pixels around intensity edges, which include disparity discontinuities.
Recently, a new approach to stereo vision called segmentation-based stereo has been proposed. These methods segment the image into regions likely to have similar or smooth disparities prior to the stereo computation. A smoothness constraint is then enforced for each segment. Tao et al. [2] used a planar constraint, while Zhang and Kambhamettu [3] used the segments for local support. These methods have shown very promising results in accurately handling disparity discontinuities.
It is noted that in the preceding paragraphs, as well as in the remainder of this specification, the description refers to various individual publications identified by a numeric designator contained within a pair of brackets. For example, such a reference may be identified by reciting, “reference [1]” or simply “[1]”. Multiple references will be identified by a pair of brackets containing more than one designator, for example, [2, 3]. A listing of references including the publications corresponding to each designator can be found at the end of the Detailed Description section.